1. Field of the Invention
The invention relates to an emission analysis device, method and system for identifying a defective location by detecting an emission of a semiconductor device.
2. Related Art
When a failure is detected in a semiconductor device, an emission analysis device for detecting an emission of the semiconductor device is used in order to identify a defective location. For example, a hot electron is generated due to a high field generated in a semiconductor element such as transistors, and this hot electron can cause the emission of the semiconductor device. Furthermore, abnormal current flows in the semiconductor elements or wires connecting the semiconductor elements, and heat is generated. The heat can also cause infra-red emission. Therefore, by using the emission analysis device, the defective location in the semiconductor device can be identified by comparing the emission of nondefective semiconductor device with that of defective one to detect a difference therebetween.
JP-A No. 2004-45132 (Kokai) (hereinafter, “Patent Document 1”) discloses a technique to identify the defective location by inputting a plurality of test patterns to the semiconductor device without failure and that with failure, obtaining images obtained by integrating the emission of each semiconductor device, and detecting a difference between the both integrated images.
However, it is difficult to detect the difference from the integrated images although there is a difference of the emission timing between the both semiconductor devices. Furthermore, because Patent Document 1 detects only integrated image, there is a problem that even if there is a difference between the emissions of the both semiconductor devices on a specific test pattern, it cannot be detected that on which test pattern the difference of the emissions occur. In addition, when an occurrence frequency of the difference of the emission is extremely small comparing to the number of test patterns to be inputted, there is a likelihood that the difference cannot be detected correctly.